A cyclone separator for a biomass circulating fluidized bed boiler

Abstract

The utility model discloses a cyclone separation device for biomass circulating fluidized bed boiler, including cylinder, cone and corrosion -resistant center cylinder, the cone fixed mounting at the bottom of cylinder, the top of cylinder is equipped with the cover ring, the ring hole of cover ring is fixedly installed with the corrosion -resistant center cylinder, the lateral surface top of cylinder is equipped with the air inlet pipe, and the bottom end of center cylinder extends to the cylinder cavity of cylinder and is connected with the shunt head through the shunt head support, and the outer cylinder wall on the corrosion -resistant center cylinder in cylinder is equipped with spiral reinforcing rib, and the air inlet end of air inlet pipe is installed with the flow head. Advantageous effect lies in: separation efficiency is high, and separation effect is good, and the corrosion -resistant and anti -deformation ability of center cylinder is good, and the service life is long, and the existing cyclone separator is convenient to the reform, and the original structure does not need obvious change, and the replacement cost is low, and the effect is obvious, and prolongs the overall service life of circulating fluidized bed boiler.

Description

Technical Field

[0001] This utility model relates to the field of cyclone separators, and in particular to a cyclone separator for a biomass circulating fluidized bed boiler. Background Technology

[0002] A biomass circulating fluidized bed boiler is a pressure-bearing special equipment that uses biomass as fuel and water, thermal oil, or related media to provide heat, hot water, steam, or power generation for domestic, industrial, or power purposes. It is mainly used for power plant generation, combined heat and power, industrial and domestic services, waste incineration, and wind, solar, and energy storage combined operations. Biomass circulating fluidized bed boilers have a wide range of applications, high thermal efficiency, and are more likely to achieve a circular economy. They have developed rapidly in recent years. Its core equipment component is a cyclone separator, which can effectively realize the return of flue gas particles.

[0003] In the production of pipe piles and most concrete components, the "double steam process" is mostly used, with steam as the main heating medium. However, due to environmental protection requirements, many coal-fired boilers used for pipe pile maintenance have been shut down in various places. Natural gas boilers have higher steam production costs. Currently, many pipe pile manufacturers use medium- and low-pressure biomass boilers with circulating fluidized beds to produce saturated steam. However, biomass boilers generate significant corrosion during steam production, especially in the central cylinder of the cyclone separator. After about two years of use, unevenly sized corrosion pits appear on both the inner and outer surfaces of the central cylinder. After a period of normal load operation, perforations of varying sizes appear in the corrosion pits of the central cylinder. The main reasons are as follows:

[0004] During testing, the corrosion micro-area contained a large amount of chlorine, and the deposits attached to the corrosion pit also contained metal compounds such as Ca, K, Na, Si, Fe, Mg, Al, and Li.

[0005] Biomass pellets, made from wood dust (containing adhesive), waste plastics, scraps, wood chips, bamboo strips, etc. collected from construction templates and furniture production, contain certain amounts of elements such as Cl, Na, K, Mg, Al, and Ca. After being preheated and burned in the furnace, they undergo pyrolysis to produce Cl2 and acidic gases. These gases react with metals to form low-melting-point eutectic compounds, which have a strong corrosive effect on the central cylinder at high temperatures. In addition, metal elements such as K, Na, Ca, Mg, Al, and Li are released from the fuel into the flue gas or distributed in the fly ash at high temperatures, and combine with acidic components in the flue gas to form alkali metal compounds, which also corrode alloy materials.

[0006] Currently, the central cylinder of the cyclone separator used in biomass circulating fluidized bed boilers is mostly made of ZG4Cr. 26 Ni6Mn3NRe alloy cast steel, due to the reasons mentioned above, will cause the following problems:

[0007] The cyclone separator's central cylinder is severely corroded and worn;

[0008] The furnace chamber and the rear heating area are severely affected by ash;

[0009] The return process was ineffective, and the system was unstable.

[0010] The lifespan of the center cylinder is relatively short.

[0011] Therefore, how to effectively improve the above situation is a major technical problem for technicians in this industry. Utility Model Content

[0012] The purpose of this invention is to provide a cyclone separator for a biomass circulating fluidized bed boiler in order to solve the above-mentioned problems.

[0013] This utility model achieves the above objectives through the following technical solutions:

[0014] A cyclone separator for a biomass circulating fluidized bed boiler includes a column, a cone, and a corrosion-resistant central cylinder. The cone is fixedly installed at the bottom of the column, and a cover ring is installed at the top of the column. The corrosion-resistant central cylinder is fixedly installed in the annular hole of the cover ring. An air inlet pipe is installed on the top side of the column. The bottom end of the central cylinder extends into the cylinder cavity of the column and is connected to a flow divider head via a flow divider head bracket. The outer wall of the corrosion-resistant central cylinder inside the column is provided with spiral reinforcing ribs, and a flow limiting head is installed at the air inlet end of the air inlet pipe.

[0015] Furthermore, the corrosion-resistant central cylinder is a two-section cylinder, with the diameter of the corrosion-resistant central cylinder above the cover ring being larger than the diameter of the corrosion-resistant central cylinder inside the column cylinder.

[0016] Furthermore, both the bottom of the column and the top of the cone are fitted with cylindrical flange rings, and the two cylindrical flange rings are fixed together by bolts.

[0017] Furthermore, a disc-shaped reinforcing rib is connected between the top surface of the cover ring and the corrosion-resistant central cylinder.

[0018] Furthermore, the distributor head support is an L-shaped frame, and at least two sets of the L-shaped frame are provided.

[0019] Furthermore, the intake pipe consists of a pipe body and a pipe mounting ring installed on the inlet end side of the pipe body.

[0020] Furthermore, the flow limiting head consists of a funnel-shaped tube, a flow limiting head mounting ring installed at the wide opening of the funnel-shaped tube, and a funnel-shaped tube installed at the narrow opening of the funnel-shaped tube. The flow limiting head mounting ring and the tube mounting ring are fixed together by bolts.

[0021] The beneficial effects are: the cyclone separator for biomass circulating fluidized bed boilers described in this utility model has high separation efficiency and good separation effect;

[0022] The central cylinder has good corrosion resistance and deformation resistance, and a long service life;

[0023] It facilitates the modification of existing cyclone separators, requires no significant alteration to the original structure, has low replacement costs, yields significant benefits, and extends the overall service life of circulating fluidized bed boilers. Attached Figure Description

[0024] Figure 1 This is an external structural diagram of a cyclone separator for a biomass circulating fluidized bed boiler as described in this utility model;

[0025] Figure 2 This is a schematic diagram of the corrosion center tube of a cyclone separator for a biomass circulating fluidized bed boiler as described in this utility model;

[0026] Figure 3 This is a schematic diagram of a flow-limiting head for a cyclone separator for a biomass circulating fluidized bed boiler, as described in this utility model.

[0027] Figure 4 This is a schematic diagram of the use of a cyclone separator for a biomass circulating fluidized bed boiler as described in this utility model.

[0028] The annotations in the attached figures are explained as follows:

[0029] 1. Column; 2. Conical tube; 3. Corrosion-resistant central tube; 4. Cover ring; 5. Inlet pipe; 51. Tube body; 52. Tube mounting ring; 6. Flow restrictor; 61. Bucket-shaped tube; 62. Flow restrictor mounting ring; 63. Bucket inlet insert; 7. Spiral reinforcing rib; 8. Flow divider support; 9. Flow divider; 10. Cylinder flange ring; 11. Disc reinforcing rib; 12. Furnace exhaust pipe; 13. Return component; 14. Boiler. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0031] The following is combined Figures 1 to 3 The cyclone separator for a biomass circulating fluidized bed boiler provided in this embodiment will be further described as follows:

[0032] This utility model provides a cyclone separator for a biomass circulating fluidized bed boiler, including a column cylinder 1, a cone cylinder 2, and a corrosion-resistant central cylinder 3. The cone cylinder 2 is fixedly installed at the bottom of the column cylinder 1, and a cover ring 4 is installed at the top of the column cylinder 1. The corrosion-resistant central cylinder 3 is fixedly installed in the annular hole of the cover ring 4. The corrosion-resistant central cylinder 3 is a slender 316 stainless steel cylinder, and its size is longer than the existing central cylinder size on the market. For example, the central cylinder size of existing medium-sized cyclone separators is mostly 900×12×1800mm. In this embodiment, under the same cyclone separator shell size, the size of the corrosion-resistant central cylinder 3 is changed to 850×10×1950mm, which is smaller than the existing cylinder diameter and longer.

[0033] An air inlet pipe 5 is installed on the top side of the column 1. The airflow in the air inlet pipe 5 enters the column 1 tangentially and swirls down in the cavity between the column 1 and the central cylinder 3. The bottom end of the central cylinder 3 extends into the cavity of the column 1 and is connected to a splitter head 9 through a splitter head bracket 8. The splitter head 9 is a cone with an inward groove on the outer side. The splitter head 9 is used to push the airflow that rises directly from the bottom outward, so that some of the gas with dust re-merges with the swirling airflow on the side and swirls again. Most of the gas is discharged through the corrosion-resistant central cylinder 3.

[0034] The outer wall of the anti-corrosion central cylinder 3 inside the column cylinder 1 is provided with spiral reinforcing ribs 7. In order to achieve the anti-corrosion performance of the anti-corrosion central cylinder 3, it is made of 316 stainless steel, but it is easy to deform. Through the spiral reinforcing ribs 7 integrated with it, its resistance to deformation is stronger, and the spiral reinforcing ribs 7 also have a certain positive effect on the generation of swirling airflow.

[0035] A flow restrictor 6 is installed at the air inlet end of the air inlet pipe 5. The flow restrictor 6 is mainly used to reduce the air inlet cross section. Combined with the size optimization of the anti-corrosion central cylinder 3, it can increase the flue gas velocity and improve the separation efficiency.

[0036] like Figures 1-3 As shown, embodiments of this utility model also disclose the following more optimized specific structures:

[0037] The corrosion-resistant central cylinder 3 is a two-section cylinder, with the diameter of the corrosion-resistant central cylinder 3 above the cover ring 4 being larger than the diameter of the corrosion-resistant central cylinder 3 inside the column cylinder 1.

[0038] Both the bottom of the column cylinder 1 and the top of the cone cylinder 2 are equipped with cylinder flange rings 10. The two cylinder flange rings 10 are fixed by bolts, and a high-temperature resistant sealing gasket is placed between them to enhance the sealing effect.

[0039] A disc-shaped reinforcing rib 11 connects the top surface of the cover ring 4 and the corrosion-resistant central cylinder 3.

[0040] The distributor head support 8 is an L-shaped frame, and at least two sets of the L-shaped frame are provided. The top of the L-shaped frame is connected to the bottom ring of the anti-corrosion central cylinder 3.

[0041] The intake pipe 5 consists of a pipe body 51 and a pipe mounting ring 52 installed on the inlet side of the pipe body 51.

[0042] The flow limiting head 6 consists of a funnel-shaped tube 61, a flow limiting head mounting ring 62 installed at the wide opening of the funnel-shaped tube 61, and a funnel inlet tube 63 installed at the narrow opening of the funnel-shaped tube 61. The flow limiting head mounting ring 62 and the tube mounting ring 52 are fixed by bolts.

[0043] like Figures 1-4 The cyclone separator for biomass circulating fluidized bed boiler shown is mainly used for the separation and reflux of flue gas particles in biomass circulating fluidized bed boiler. The bottom of the cyclone separator for biomass circulating fluidized bed boiler is connected to the boiler 14 through the reflux component 13, and the green exhaust pipe 12 at the top of the filter 14 is connected to the air inlet pipe 5.

[0044] In the above structure, the gas intake volume in the boiler remains unchanged. After passing through the flow restrictor 6, the gas enters the interior of the column 1 through the intake pipe 5. When the swirling gas encounters the cone 2, medium and large particles fall down, while micro particles rise with the rising gas. After passing through the diverter 9, some small particles can easily re-enter the swirling gas on the side under the action of the arc surface of the diverter 9. Other gases are discharged through the corrosion-resistant central cylinder 3, and the flue gas velocity at the internal throat increases, further improving its separation efficiency.

[0045] The cyclone separator for biomass circulating fluidized bed boilers described in this embodiment can also modify the material of the existing alloy cast steel central cylinder. The specific modification of the central cylinder is as follows:

[0046] First, use a pneumatic hammer to remove the refractory casting surface of the left wall of the evaporator and the hanging layer of the throat pipe. Remove the masonry surface and wear-resistant material of the central tube outlet slope. The original central tube flange and stiffener are retained. The corrosion-resistant central tube 3 is introduced, positioned and adjusted. Then, the level is calibrated and finely adjusted to ensure the horizontality and verticality. After welding, it is recast and restored.

[0047] The flow restrictor 6 can be directly added to the flange between the furnace exhaust pipe 12 and the inlet pipe 5, and is easy to install via the flow restrictor mounting ring 62.

[0048] When modifying some existing cyclone separators, the central cylinder size of 900×12×1800mm was changed to 850×10×1950mm in this embodiment (the length here refers to the internal cylinder length). The separation efficiency was improved, and the inlet flue gas velocity increased from the original 18.0m / s to between 19.6m / s and 20.4m / s. This met the requirements for the amount of external circulating material and the ash concentration in the furnace under high load conditions, and the combustion conditions were adjusted and optimized, resulting in a certain degree of improvement in boiler thermal efficiency.

[0049] After the modification, the fluidized bed boiler bed temperature decreased by more than 15-25℃, the bed temperature deviation was reduced, and the temperature difference between the left and right return feeders gradually became more uniform, with less temperature fluctuation. This indicates that the optimized structure of the separation center cylinder has a significant impact on improving the separator's separation efficiency. Furthermore, the median fly ash diameter decreased from 52μm to 30μm, directly demonstrating a significant improvement in the boiler separator efficiency after the modification. The fly ash burnout rate is better, and load increases are easier to achieve. Based on the material balance principle, the separator efficiency can be calculated using the differential pressure in the dilute phase region. Considering that the pressure loss from the material sidewall flow accounts for approximately 10%-12% of the furnace pressure drop, the modified formula shows that the separator efficiencies before and after the modification are 93.24% and 97.86%, respectively, representing an efficiency improvement of 4.62%.

[0050] Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of this utility model as claimed.

Claims

1. A cyclone separator for a biomass circulating fluidized bed boiler, characterized in that: The device includes a cylindrical tube (1), a conical tube (2), and an anti-corrosion central tube (3). The conical tube (2) is fixedly installed at the bottom of the cylindrical tube (1). A cover ring (4) is installed at the top of the cylindrical tube (1). The anti-corrosion central tube (3) is fixedly installed in the annular hole of the cover ring (4). An air inlet pipe (5) is installed on the top side of the cylindrical tube (1). The bottom end of the central tube (3) extends into the cavity of the cylindrical tube (1) and is connected to a flow divider (9) through a flow divider bracket (8). The outer wall of the anti-corrosion central tube (3) inside the cylindrical tube (1) is provided with spiral reinforcing ribs (7). A flow limiting head (6) is installed at the air inlet end of the air inlet pipe (5).

2. The cyclone separator for a biomass circulating fluidized bed boiler according to claim 1, characterized in that: The corrosion-resistant central cylinder (3) is a two-section cylinder. The diameter of the corrosion-resistant central cylinder (3) above the cover ring (4) is larger than the diameter of the corrosion-resistant central cylinder (3) inside the column cylinder (1).

3. The cyclone separator for a biomass circulating fluidized bed boiler according to claim 1, characterized in that: Both the bottom of the column (1) and the top of the cone (2) are equipped with cylindrical flange rings (10), and the two cylindrical flange rings (10) are fixed by bolts.

4. The cyclone separator for a biomass circulating fluidized bed boiler according to claim 1, characterized in that: A disc reinforcing rib (11) is connected between the top surface of the cover ring (4) and the anti-corrosion central cylinder (3).

5. A cyclone separator for a biomass circulating fluidized bed boiler according to claim 1, characterized in that: The diverter head bracket (8) is an L-shaped bracket, and at least two sets of the L-shaped bracket are provided.

6. A cyclone separator for a biomass circulating fluidized bed boiler according to claim 1, characterized in that: The intake pipe (5) consists of a pipe body (51) and a pipe mounting ring (52) installed on the inlet side of the pipe body (51).

7. A cyclone separator for a biomass circulating fluidized bed boiler according to claim 6, characterized in that: The flow limiting head (6) consists of a funnel-shaped tube (61), a flow limiting head mounting ring (62) installed at the wide opening of the funnel-shaped tube (61), and a funnel inlet tube (63) installed at the narrow opening of the funnel-shaped tube (61). The flow limiting head mounting ring (62) and the tube mounting ring (52) are fixed together by bolts.

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